Displacement valve gas lift



June 2, 1942.4 IM. P. BURKE DISPLACMENT VALVE GAS LIFT 2 Sheets-Sheet 1 Filed June 8, 1959 June 2', 1942.-

M. P. BURKE DEPLACEMENT VALVE GAS LIFT Filed June 8, 1959 2 She ets-Sheet 2 In Ven tar [27mm I? Zwzf' orney Patented June 2, 1942 UNiTED STATES Parar orrics 2,285,109 DISPLACEMENT VALVE GAS LIFT Mark P. Burke, Long Beach, Calif.

Application June 8, 1939, Serial No. 278,110

9'Claims. (Cl. 10S-232) This invention relates to apparatus for pumping liquids from wellsvr and is particularly concerned with a displacement valve gaslift. -Inventions of this general type have been shown in my Patent `No. 1,803,837 entitled Gas lift means, issued to me March 5, 1931, and my copending applications for U. S, Letters Patent entitled Flu-id lift and Fluid operated means, filed April 2l, '1938, and bearing Serial Numbers 203,451 and 203,452, now Patents 2,259,949, October 2l, 1941, and 2,251,323, August 5,1941, respectively.

At the present time it is necessary that oil well pumping equipment be designed to meet 4all prevailing con-ditions, such as those caused by differences in Vfluid yield and liquid head and other conditions arising because of proration restrictions to control the outputjof Wells ina given field and to regulate production generally. In

my Patent No. 1,803,837, previously mentioned.v

I have shown a structure for use in small wells where there is not a sufficient liquid head standing within the Well to prevent gas from breaking through the liquid column and causing it to get out of control. tion the valve shown `is of the bellows type, which opens when a surface intermitter'opens the surface control valve allowing the fluid under pressure to force the slug of liquid from the Well and to close when the surface intermitter stops the `flow -ofiluid-into the well, allowing gas toescape through the flow tube until the gas pressure'is less than the spring `pressure of the valve. The fluid control valve, as shown in that patent, is placed above a liquid accumulating chamber,

and when the valve is opened the fluid pressure is exerted downwardly on the liquid in the charnber and the liquid is then forced up into a macaroni tube and out of the well. The accumulating chamber is shown in that patent as being a multiplying chamber since the volume of liquid which has accumulated in this chamber is forced upwardly into a pipe of smaller cross-sectional area, giving the liquid an additionalI fluid head. -In that particular case a surface control valve with an intermitter is shown as providing a control for the fluid which supplies the lifting* force in the Well.

v'As previously stated, the Idevice of the patent has been designed for use `in wellsl having a rela- In that particular construc- It is the principal object of the present invention, thereforeto provide a fluid lift structure Which will operate efficiently in wells Within which a high lift liquid level and large potentials exist, and which will respond to the standard pressure of a lifting uid available for the purpose.

The present invention contemplates the provision of a surface intermitter and a control valve which governs the pressure flow of a lifting fluid conducted to the pumping apparatus in the well. A liquid control valve is also provided Yto permit only a predetermined amount of liquid to enter the tube, and a pressure fluid control valve isV disposed in the lower end of the flow tubing above the liquid control valve, and it cooperates therewith in -a maner to insure that when the fluid contrclvalve is opened the pressure ofy the pressure fluid is exerted upwardly against the accumulated column of liquid and forces this slug of liquid out of the well. The structure also contemplates the provision of an enclosed chamber Within which the pressure fluid control valve and the liquid control valve are encased, said chamber being in communication with the space around the valves in the tubing, thus permitting any leakage of fluid to escape through an exhaust valve during the cycle of pressure change which occurs when the liquid is being forced from the well and after the slug has been discharged, the valves being so arranged t as to prevent them from becoming fluid locked since the fluid pressure within the chamber is freeV to equalize with the pressure in the space around the valves after theslug Yhas been forced from the well and the pressure is almost atmospheric pressure. With Ythe uid lifting mechanism here shown it is proposed to use an intermitter and surface control valve such as 'disclosed in my co-pending application filed by me in the U. S. Patent Office on April y21, 1938,.,Ser`ial No. 203,452, and which application is entitled Fluid operated means, new Patent 2,251,323, August tively low hydrostatic uid head and would not operate with the greatest of eflciency in wells which have a relatively high liquid level and hydrostatic head and have `a yield of cognant fluid of large potential.

, The invention is illustrated by way of examplein the accompanying drawings, in which:

Figure 1l is a View in section and elevation with parts brok-en away showing the application of the present invention to a Well.

Fig. 2is an enlarged vieWin longitudinal section through the fluid control valve structure, as

seen on the line 2 2 of Fig. 1.

Fig. 3 is ran enlarged view in central longitudinal section through the automatic liquid control valve, as seen on the line 3 3 -of Fig. 1.

gas under pressure is delivered to the top of the well. A cut-off valve structure II is interposed 'in this gas line and is controlled by surface intermitter I2, the details of which are more clearly disclosed in my co-pending application, .as aforementioned. The intermitter acts'to establish a flow of gas to the well in predetermined volume and Apressure and for a predetermined period, after which the ow of gas is interrupted for a predetermined periodjduring which a liquid column will accumulate within the flow pipe, as will be hereinafter described. The pressure fluid, after passing through the valve II, travels through pipe I3 to the casing I4 with which the pipe is connected. This casing extends downwardly into the well and is shown as being fitted at its lower end with a perforated well screen section I5. A suitable casinghead I6 is fastened at the upper end of the casing I4 and through whichl a ow tube I1 extends. The flow tube I1 extends downwardly to a point adjacent the lower end of the well where its open end I8 is free to receive cognate uid from the formation surrounding the well screen I5. Mounted adjacent the lower end of the ow tube I1 is a standing valve I9 provided with a valve ball I9.

At a suitable point in the length of the casing a packer 2l) is mounted upon the tubing and forms a fluid seal between the well easing and the tubing so that a well iluid compartment 2I will occur beneath the packerV and prevents the well fluid from passing upwardly only through the ow tube I1.

Mounted within the ow tube I1 and above the standing valve I9 is a liquid control valve unit 22. This unit is shown more particularly in Fig. 3 of the drawings. The liquid control valve unit includes an equalizing valve housing 23 suitably secured within the flow tube I1. This valve housing is formed with aV valve chamber 24 having an upper wall 25 and a lower wall 2B. The upper wall is formed with a central downwardly presented valve opening and seat21., and the lower wall is formed with a central downwardly presented valve opening and seat 28. An equalizer valve spool 29 extends through 4the valve opening 28 and carries an upper valve element 30 adapted to seat against the valve seat 21 and a lower valve element 3l adapted to seat against the valve seat 28. These valve elements are of the poppet type. The valve spool 29 is slidably mounted upon a valve stem 32, which stem is threaded into the lower end of an exhaust tube 33. Formed centrally through the stem 32 is an equalizer passage 34. Interposed between the lower end of the exhaust tube 33 and the upper face of valve 30 is a valve spring 35. Interposed between the lower face of the valve element 3| and a nut 33 is a valve spring 31. By this means it will be seen that the valve spool 29 will be supported yieldably upon the valve stem 32 and will seat irrespective of minor variations and movement of the valve stem and the exhaust tube,

The lower valve element 3l is mounted to reciprocate within a downwardly extending cylindrical extension 38, which extension is closed at its lower end by a threaded plug 39. The valve element 3I has a sliding i-lt within the extension 38 and the fluid space below the valve is in communication with the equalizing passageway 34 which leads upwardly through the exhaust tube 33 and is closed at its lower end by an exhaust valve 40. The exhaust valve 40 includes a threaded valve seat 4I having a port 42 therethrough, which is closed by a valve ball 43. The valve ball 43 is yieldably held upwardly to its seated position by a spring 44. Thus, fluid may pass downwardly through the valve port 42 but cannot pass upwardly.

At a point in the length of the exhaust tube 33 are exhaust ports 45 which extend through the wall thereof. With this arrangement uid pressure on opposite sides of the exhaust Valve structure 23 will be equalized after the slug has been forced from the well. The upper end wall 25 of the equalizer valve housing 23 carries a guide bearing 46 through which the exhaust tube 33 may reciprocate.

The upper end of the exhaust tube 33 is threaded into the lower end of a tubular valve plunger 41. This plunger is cylindrical and has a central chamber 48 extending longitudinally therethrough. At a point intermediate the ends of the plunger an enlarged outside collar 49 occurs. This collar has a lower tapered valve shoulder 50 and an upper tapered valve shoulder 5I. The portion of the plunger below the shoulder 50 extends into a lower valve sleeve 52. The sleeve has a central cylindrical bore with relation to which the valve plunger has a free fit. A tapered valve seat 53 is formed at the upper end of this bore and against which the valve shoulder 55 rests. A tapered valve seat 54 is formed at the lower end of this bore and receives a tapered valve face 54 formed on the end of the plunger 41. The exhaust tube 33 extends through a central opening in the lower valve sleeve 52. Thus, it will be seen that the exhaust tube 33 and the valve spool 29 are carried by the valve plunger 41 and moved therewith.

The lower valve sleeve 52 is mounted within a liquid control valve housing 55. This valve housing has an enlarged cylindrical lower portion which fits within the flow tube I1 and is secured in position by any suitable means, such for example as welding, as indicated at 56. Formed as a continuation of the lower enlarged portion of the housing is an upwardly extending guide tube 51. The lower portion of the housing and the guide tube are formed with a central bore 58 within which the lower valve sleeve 52 lits. At the upper end of the bore a shoulder 59 occurs and receives an upper valve seat 60. The upper valve seat 60 is suitably spaced from the lower valve sleeve 52 by a spacing bushing 6I. The valve seat 60 has a central opening therethrough to receive the upper extending end of the plunger 41 and is formed with a tapered valve face '62 against which the tapered shoulder 5I on the plunger 41 may seat. It will'be seen by an examination of Fig. 3 of the drawings that the space between the shoulders 5l) and 5I on the plunger is less than the space between the faces 53 and 62 of the lower and upper valve seats 52 and 60, respectively. This spacing is represented by the height of the spacing bushing 6I.

The guide tube 51 extends upwardly a distance above the upper end of the plunger 41 and provides a chamber within which a plunger spring 63 is mounted. This spring rests against the upper face of the plunger 41 and is held in position byan adjusting nut 64 which has a fluid passageway 65 therethrough. The upperA end of the guide tube 51 is closed by a plug 66.

The lower end of the liquid control valve housing 55 carries a tubular lock nut 61 which is threaded into the bore 58 and rests against the lower face of the valve sleeve 52.

Attention is directed to the fact that the bore through the valve seat 54 of the lower valve sleeve 52 is materially larger vthan the diameter of the exhaust tube 33, thus providing a uid passageway 68.

It is also to be pointed out that the guide bearings 46 are supported by-arms permitting a free ilow of fluid through the valve openings 21, and

28 of the equalizer valve structure, and that in addition liquid ports 69 are formed through the wall 26 of the equalizer valve housing. This establishes direct communication between the equalizer valve chamber 24 and the space occurring below the equalizer `valve and above the standing valve. Liquid ports are formed longitudinally through the liquid control valve housing 55 to establish communication between the chamber 1I and the flow passageway 12.

Mounted within the flow tube I1 at a point above the liquid control valve and the'equalizer valve is a fluid control valve. This comprises a control valve housing 13 having an enlarged portion 14 which fits withinthe ow tube I1 and a reduced downwardly extending Vtubular portion 'i5 which extends down into the flow passageway 12. Liquid ports 16 extend through the enlarged portion 14 of the housing 13 and establish communication between the flow passageway 12 and the unrestricted upper length of flow tube.

The upper end of the housing 13 is formed with a central cylindrical bore k11 which terminates in a shoulder 18. A restricted bore 19 continues downwardly through the portion of the housing. The shoulder 18 is formed with a tapered valve seat 88 adjacent to which a spacing bushing 8I is positioned. Restingupon the upper edge of this spacing bushing is an upper valve sleeve 82 formed with a tapered valve seat 83. A central opening 84 through the valve seat 83 has been designed to determine the pressure f area for a movable valve plunger 85. This valve plunger is cylindrical, having an upper portion iitting within the valve sleeve 82 and a 'lower portion fitting within the bore 19 of the housing extension 15. able valve plunger is formed with a tapered face 86 which rests against the valve seat 83 in the upper valve sleeve 82. Attention is directed to the fact that the end face of the plunger 85 is exposed to pressure exerted through the opening 8d in the valve sleeve 82. Threaded into the upper end of the bore 11 vof the Vvalve housing 13 is a plug 81 which has a cavity in its underv face to form a chamber 88. Fluid inlet ports 89 extend radially through the side wall of the plug 81 and through the body portion of the valve housing 13. These ports also pass through openings in the ilow tube I1 to establish communication between the chamber 88 and the pressure iluid passageway 90. This passageway occurs between the flow tube I1 and the casing I4.

Formed through the side wall'of the valve sleeve 52 and communicating with the liquid ports 16 in the housing 13 are pressure uid outlet ports 9|'. These ports are effectively 'closed The upper end of the movwhen the movablevalve plunger 85 is in its uppermost position. The lower end of the valve sleeve 82 is provided with a tapered seat'92 spaced from the tapered seat 88 within the housing extension 15." Occurring between these seats is an enlarged cylindrical portion 93 formed on the 'circumference of the plunger 85 and a vpoint space therein.

ypass through it. The lower end of the bore 19 -isclcsed b! a plug 89.

An exhaust valve |00 is mounted within the plug 99 and will permit k flow of iiuid outwardly from the bore but will in Fig. 2 of the drawings.

seatV 21. It will then pass'on upwardly into the chamber 1l and will rise vthrough the liquid ports formation.

- tube E1.

prevent the ilow of uid inwardly thereto.

In operation of the present invention the structure is shown assembled vand installed, as indicated .particularly in Fig. 1. It will be understood that the casing I4 is set in the well with the well strainer I5 disposed'in the productive The ow tube I1 is then lowered into the well and its packer V20 is suitably set to create a passagewaySiJ for fluid under pressure above the packer and around the ilow tube I1, and a passageway '2i below the packer and around the flow tube. By this arrangement fluid under pressure may be delivered from the pipe Il] through the valve 'II and the pipe I3 to the casing. Also by this arrangement the cognate fluid yielded by the geological formation within which thek well screen I5 is set will ilow into the space 2| beneath Ythe packer and can only ilow upwardly through the standing valve I9 and through the flow tube I`1as controlled by the liquid control valve 22 vand the fluid control Valve, generally indicated at IGI and shown in detail The liquid from the formation will then enter the well casing through theY well screen I5, andas it fills the space 2I beneath the packer will lift the valve ball I 9 in the standing valve l 9 and will enter the chamber ill?. At this timev the valve spool 29 will be inits lowermost position, and the plunger 41 will'be in its lowermost position. vThe liquid will then pass upwardly through ithe ports` 69 and into the chamber 24 and then around the equalizingV valve 'element 30 and through the Yvalve 18 and into the ow passageway 12, after which it will rise in the passageway 12 until it encounters the valve housing 13 of the fluid control valve. The liquid will then passy upwardly through the liquid yports '16 and into the flow It is assumed that there is not sulcien't pressure in the well to elevate this column of liquid to the top ofthe well and to cause it to discharge from the upper end of the ilow tube lli.r It is, therefore, necessary to provide the intermitter structure l I2. This' is so regnlated withrelation to the yield of the geological formation as 'to be actuated when the liquid to be pum'pe'dfhasv accumulated a predetermined column within the flow tube I1. Prior to this Vtime the column of liquid -accumulated within the :Elow y tube I1 and down into the chamber 1I will be suflicient to overcome the resistance offered by the valve plunger 41 and its spring 63 to move the valve plunger 41 upwardly, and to at the same time seat the valve elements 30 and 3| on the spool 2S. When the valve element 30 is forced against its seat 21 the upward flow of liquid will be interrupted and the desired quantity, as represented by the height of the liquid column, will be entrapped within the structure preparatory to being elevated by the pressure of gas supplied from the pipe I through the intermitter valve II. This is accomplished when the intermitter I2 opens the valve II and causes a charge of gas to be forced downwardly within the casing and around the tube |`1. Its downward path will be interrupted by the packer and the gas will be diverted through the gas inlet ports 89 and into the chamber 88 in the top of the uid control valve IOI. This pressure will then be sulicient to act upon the surface area of the end of the plunger 85 and force the plunger downwardly so that its tapered end face 86 to overcome pressure of spring 91 will move to an unseated position with relation to the tapered face 83. The gas will then flow through the opening 84'and through the ports 9| into the liquid ports 16, where it will be delivered beneath the column of liquid accumulated within the now tube I1 and will elevate and discharge this accumulated liquid as a slug from the top of the well. The intermitter I2 is set to close the valve I after the slug has been forced from the well. After the valve II is closed the gas escapes through the flow pipe until the pressure acting upon the surface area of the end of the plunger 85 is less than the pressure of the spring 91. When this condition is established the spring 91 forces the face 86 of the plunger back against the seat 83 and interrupts the flow of gas into the ow tube I1. At this time it will be evident that the ow of gas has exhausted the accumulated head of liquid within the flow tube, and thus thevalve spring `63 of the liquid control valve 22 will force the plunger 41 downwardly and will force the valve element 30 away from its seat 21. Attention is directed to the fact that since there is equal pressure on the opposite sides of the valve element 38 and 3| that the valve spool 29 will be maintained in equilibrium under balanced pressure, and that the valve will move readily to and from its desired position. By this arrangement any amount of liquid available as a yield from a well may be pumped, and the pressure required to actuate the structure will always be the same since theliquid control valve will allow only a certain amount of liquid to enter the tubing at each cycle of its operation. It is to be understood that the joint I use of liquid control valve 22 and the fluid control valve ||I| is desirable in order to control operation in the event the liquid head should create a pressure greater than that of the operating fluid. The valves might serve useful purposes when used separately, as for example in connection with the structures as shown in-my above mentioned co-pending applications, Serial No. 203,451 and Serial No. 203,452, now Patents 2,259,949, October 21, 1941, and 2,251,323, August 5, 1941, respectively.

In further explanation of the valve operation it is to be pointed out that the fluid passageways 48 and 65 within the valve structure shown in Fig. 3 of the'drawings form an enclosed chamber which is maintained at substantially atmospheric pressure. The plunger 41 within which chamber 48 vis formed is movable and is held downwardly in its closed position by spring B3. When well fluid rises within the tubing I1 it will exert a pressure on the portion of the plunger 41 which isexposed through the opening 68 in the member 52. At this time the equalizing valve element 30 will be submerged within the rising well uid. When the valve elements 3D and 3| are in their normal opened position as shown in Fig. 3 the liquid pressure is exerted on all sides of the valve elements within chambers 24 and 1I and within 'the chamber enclosing the nut 36. The pressure acting against the portion of the plunger 41 exposed through the opening 68 is equal to the fluid head times the entire area ofthe opening 68 the same as if the member 33were removed. When the well fluid reaches a height at which the pressure exerted against the end of the plunger 41 is suicient to overcomeV the resistance of spring 63 the plunger 41 is forced from its seat at .54' and an additional area of the end of theplunger is ex posed. This causes the plunger to be forced upwardly within the member '52 in a rapid movement which compresses the spring 63- and lifts the valve elements 30 and 3| so that they will be forced against their seats' 21 and 28 to interrupt the inflow of well fluid. The pressure of the well fluid from within the well is then exerted against the bottom of the valve element 30 and against the top of the valve element 3|, these elements being'of equal area. The passageways 34 and 45 will allow the pressures to remain equal in chamber 1I and in the chamber containing the nut 36. Due to this equal pressure the valve can be opened and closed without effort. When the plunger 41 is seated it seals the chamber 65 at 54 and seals it at 68 when open. It is evident that some leakage will occur while the plunger 41 is moved from open to closed Dosition. This liquid will accumulate in the bottom of the passageway 48 above the exhaust valve 48. As this liquid accumulates the air in chamber 65 and passageway 48 will be compressed and a pressure will be created which will exert a force on the top of the plunger 41 and within lthe passageway 48 to open the exhaust valve until the pressure within the passageway 48 and that within the chamber 1| are equal. When this pressure reaches a point higher than the pressure in chamber 1I which will be at the lowest point in the pumping cycle liquid will be forced out through the exhaust valve 4U and through the passageway 45 into the chamber 1|. If it were not for the system of thus exhausting the fluid which leaks into passageway 4B the valve would become fluid locked and would not function.

With particular reference to Fig. 2 of the drawings, it will be seen that the movable valve element acts normally to close the ports 9| and to prevent communication between the flow pipe I1 and the gas 'inlet chamber 88. It will also be evident that due to the arrangement of ports 9| in a plane transversely of the movable valve element and at a point below the lower end thereof the pressure exerted by a column of liquid standing in the flow pipe |`1 will have no effect upon the movable valve element 85 to move it from its upper and seated position. It will further be noted that the column of liquid will not afford frictional resistance to the movement of the element save as such surface resistance created by the pressure of the liquid against the fitted with ports through which pressure fluid cylindrical side walls of the element in the area of the ports 9|. When gas is introduced into the chamber 88 the movable valve element 85k will be acted upon through the bore 84 at the upper end of the sleeve 82. VAt the instant the valve element 85 is moved downwardly it will be evident that a greater end surface area of the valve element will be uncovered, tending to increase the pressure action on the valve, snapping it against its opposite seat. As the valve moves downwardly it will compress the spring 91, and tapered end faces will rest on seat 80 sealing the chamber around the outside of the plunger when the valve is open. Fluid may have leaked around the movable valve element as it was opened and closed and thus created an accumulated pressure. In any event it will be seen that the pressure of the fluid within the valve housing and within the cavity of the movable valve element will represent the lowest pressure existing in the flow tube and on the outside of the check valve lill! at any point in the cycle of operation of the pumping' apparatus.

It will thus be seen that by the construction and arrangement here shown it is possible to completely control and pump a well within which a large or small flow of liquid accumulates as the well flows, and that by the liquid-regulating means hereV disclosed it is possible to discharge the same weight of liquid at each pumping impulse as initiated by the intermitter valve and produced'by the gas controlled thereby.

While I have shown the preferred form of my invention as now known to me, it will be understood that various changes may be made in combination, construction and arrangement of parts by` those skilled in the art, without departing from the spirit ofl my invention as claimed.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

1. In a fluid lift pump mechanism, means for delivering a pressure fluid thereto intermittently a iiow tube, an automatic pressure uid valve comprising a movable valve element and a valve housing tting within the flow tube of a well fitted with ports through which pressure fluid may pass when the valve is opened and having unobstructed uid passageways therethrough, a liquid control valve structure below the housing and within the flow tube Vthrough which a normally unobstructed iiow of liquid may pass, said structure being formed with a valve seat, a balanced valve ywithin said structure and normally unseated, a valve operating structure mounted within the liquid valve housing and being acted upon by the pressure of an accumulated column of liquid passing up through the liquid passageways of said housing and into the flow tube, whereby when a predetermined pressure of liquid has accumulated within the tube the liquid 4control valve will close and the valve operating means will move the balanced valve within the valve housing to its closed position, a cylindrical bore formed within the housing of the valve structure Vand within which a movable element connected with the balanced valve reciprocates, and a bypass duct from the cylindrical bore to a point above the balanced valve structure whereby the fluid pressure within the cylindrical bore and the liow tube may be balanced. Y l

2. In a Iiuid lift pump mechanism, means for delivering a pressure Iluid thereto intermittently a flow tube, an automatic pressure liuid valveV comprising a movable valve element and a valve housing fitting within the flow tube of a well .liquid control valve structure below the housing and within the ow tube through which a normally unobstructed flow of liquid may pass, said structure being formed with a valve seat, a balanced valve within said structure and normally unseated, a valve operating structure mounted within the liquid valve housing and being acted upon by the pressure of an accumulated column of liquid passing up through the liquid passageways of said housing and into the ow tube, whereby when a predetermined pressure of liquid has accumulated within the tube the liquid control valve will close and the valve operating means will move the balanced valve within the valve housing to its closed position, a cylindrical bore formed within the housing of the valve structure and within which a movable element connected with the balanced valve reciprocates, a bypass duct from the cylindrical bore to a point above the balanced valve structure whereby the fluid` pressure within the cylindrical boreV and the liow tube may be balanced, and a valve seat at the top of the cylindrical bore for sealing the cylindrical bore when the passage through the valve structure is closed.

3. In a fluid lift pump mechanism, means for delivering a pressure fluid theretointermittently a iow tube, an automatic pressure fluid valve comprising a movable valve element and a valve housing fitting within the ilow tube of a well fitted with ports through which pressure iiuid may pass when the valve is opened and having unobstructed fluid passageways therethrough, a liquid control valve structure below the housing and within the ilow tube through which a normally unobstructed ow of liquid may pass, said structure being formed with a valve seat, a balanced valve within said structure and normally unseated', a valve operating structure mounted within the liquid valve housing and being acted upon by the pressure of an accumulated column of liquid passing up through the liquid passageways of said housing and into the iiow tube,

whereby when a predeterminedpressure of liquid has accumulated within the tube the liquid control Avalve will close and the valve operating means willmove the balanced valve within the valve housing to its closed position, a cylindrical bore formed within the housing of the valve structure and within which a movable element connected with the balanced valve reciprocates, a bypass duct from the cylindrical bore to a point above the balanced valve structure whereby the fluid pressure within the cylindrical bore and the iiow tube may be balanced, a valve seat at the top of the cylindrical bore for sealing the cylindrical bore when the passage through the valve structure is closed, anda yieldable mounting for the valves within the valve structure with relation to the operating means.

4. In combination with a flow tube of a iiuid lift pump, a liquid control valve housing mounted within the liow tube and having liquid 'passageways therethrough, an equalizer valve housing mounted within the tube below the rst named valve housing and spaced therefrom to form a liquid chamber in communication with said passageways, a valve seat withinthe equalizer valve housing and having a face downwardly presented, a valver element within the equalizer Valve housing and normally spaced from said seat, said equalizer valve housing being formed with ports whereby a free ilow of liquid may pass upwardly through the flow tube from beneath the equalizer valve housing through the valve `housing into the chamber thereabove and then upwardly through the liquid control valve housing to the flow tube, a cylindrical bore formed within the liquid control valve housing and being closed at its upper end, a tubular valve plunger reciprocating within said bore and being open at its upper end to the space at the closed end of the bore, a valve seat at the lower end of said bore, spring means within the bore tending to force the valve plunger downwardly onto the seat, the seat having an opening therethrough whereby fluid pressure from the chamber beneath the liquid control valve housing may act against the end of the plunger to lift the same in opposition to the action of the spring and connecting means between said plunger. and the equalizer valve whereby when the liquid pressure overcomes the strength of the spring the valve plunger will lift and the equalizing valve will be seated, thereby entrapping an accumulated column of liquid within the flow tube having suicient pressure to lift the plunger, and a fluid passageway to equalize the fluid pressure on opposite sides of the equalizer valve.

5. In combination with a ilow tube of a fluid lift pump, a liquid control valve housing mounted within the flow tube and having liquid passage- Ways therethrough, an equalizer valve housing mounted within the tube below the lirst named valve housing and spaced therefrom to form a liquid chamber in communication with said passageways, a valve seat within the equalizer valve housing and having a face downwardly presented, a valve element within the equalizer valve housing and normally spaced from said seat, said equalizer valve housing being formed with ports whereby a free flow of liquid may pass upwardly through the flow tube from beneath the equalizer valve housing through the valve housing into the chamber thereabove and then upwardly through the liquid control valve housing to the flow tube, a cylindrical bore formed within the liquid control valve housing and being closed at its upper end, a tubular valve plunger reciprocating within said bore and being open at its upper end to the space at the closed end of the bore, a valve seat at the lower end of said bore, spring means within the bore tending to force the valve plunger downwardly onto the seat, the seat having an opening therethrough whereby fluid pressure from the chamber beneath the liquid control valve housing may act against the end of the plunger to lift the same in opposition to the action of the spring and connecting means between said plunger and the equalizer valve whereby when the liquid pressure overcomes the strength of the spring the valve plunger will lift and the equalizing valve will be seated, thereby entrapping an accumulated column of liquid within the flow tube having sufcient pressure to lift the plunger, the tubular plunger being open at its opposite end to the enclosed space within the bore of the liquid control valve housing and being provided with a check valve at its lower end whereby an excess amount of liquid which has leaked by the plunger and into the chamber of the housing will exhaust through the check valve.

6. In a device of the character described, a fluid flow tube within which a column of liquid stands during operation of the device, a fluid control valve mounted within the tube and substantially beneath the column of liquid, said control valve comprising a tubular housing longitudinally aligned with the tube and being closed at'its opposite ends, a fluid chamber at one end of said housing in direct communication with a source of lluid under pressure, an end wall in said chamber formed with a valve seat having a central opening therethrough, a valve element within the housing movable longitudinally and adapted to seat against the valve seat to normally close the opening therethrough, yieldable means for normally holding said movable valve element in its seated position, said housing being formed with gas outlet ports extending laterally through the walls thereof, the outer ends being in free communication with the flow tube, the inner ends being normally closed by said movable valve element and placed in communication with the uid chamber when the valve element is moved by the fluid to its open position, and means for creating a seal between the valve element and its housing when the valve elementI is in its seated position and when it is unseated.

7`. In a device of the character described, a iluid iiow tube Within which a column of liquid stands during operation of the device, a uid control valve mounted within the tube and substantially beneath the column of liquid, said control valve comprising a tubular housing longitudinally aligned with the tube and being closed at its opposite ends, a iluid chamber at one end of said housing in direct communication with a source of fluid under pressure, an end wall in said chamber formed with a valve seat having a central opening therethrough, a valve element within the housing movable longitudinally and adapted to seat against the valve seat to normally close the opening therethrough, yieldable means for normally holding'said movable valve element in its seated position, said housing being formed with gas outlet ports extending laterally through the walls thereof, the outer ends being in free communication with the flow tube, the inner ends being normally closed by said movable valve element and placed in communication with the iluid chamber when the valve element is moved by the fluid to its open position, and a check valve in the closed end of the valve housing opposite from the end within which the fluid chamber occurs, whereby pressure of fluid entrapped within the valve housing may be relieved untilV it reaches the pressure of the fluid on the outside of the valve housing.

8. In a deviceof the character described, a flow tube within which a column of liquid may stand and from which it is elevated, a valve housing mounted within said tube adjacent the lower end thereof and enveloped by the liquid in said column, said housing being closed at its opposite ends, a pressure uid chamber in the upper end of said housing, a valve chamber within the housing below said rst named chamber and in communication therewith through a vvalve opening lying in a horizontal plane, ports extending horizontally through the side wallof the housing and establishing communication between the valve chamber and the flow tube within which the column of liquid may stand,A a movable valve element within the valve chamber normally closing the ports in communication with the tube and the passageway between the fluid pressure chamber and the valve chamber whereby the pressure exerted by the column of liquid will act against the sides of the valve element and pressure exerted by the pressure fluid within the pressure chamber to act against the end of the valve element to move the same,` means for introducing iluid under pressure to the pressure chamber, and yieldable vmeans for acting upon the Valve element to normally hold it in its seated position.

9. In a device of the character described, a iow tube within which a column of liquid may stand and from which it is elevated, a valve housing mounted within said tube adjacent the lower end thereof and enveloped by the liquid in said column, said housing being closed at its op posite ends, a pressure uid chamber in the upper end Vof said housing, a valve chamber within the housing below said rst named chamber and in communication therewith throughk a valve opening lying in a horizontal plane, ports eX- tending horizontally through the side wall of the housing and establishing communication between the valve chamber and the flow tube within which the column of liquid may stand, a movable valve element within the valve chamber normally closing the ports in communication with the tube and the passageway between the ud pressure chamber and the valve chamber whereby the pressure exerted by the column of liquid will act against the sides of the Valve element and pressure exerted by the pressure fluid within the pressure chamber to act against the end of the valve element to move the same, means for introducing fluid under pressure to the pressure Chamber, yieldable means for acting upon the valve element to normally hold it in its seated position, means permitting iluid within the valve chamber to equalize in pressure with the lowest pressure of the fluid within which the valve structure is submerged, and means for closing the valve after the slug has been forced from the well because of a reduction in pressure around the valve.

' MARK P. BURKE. 

